So just something that’s been on my mind. At my workplace there’s an automatic road barrier that lifts up and down when vehicles arrive. However, it’s not used for a carpark system when people wave their tickets or something. It just goes up and down when a vehicle shows up.

However, it sometimes goes up for when say a pushcart is being rolled over whereas it wouldn’t for a guy pushing a bin.

So tldr, how does an automatic road barrier decide that yes, a vehicle is coming, and therefore opens up?

  • FuglyDuck
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    41 year ago

    Could be a lot of ways- an IR beam some where before the barrier. A motion sensor (usually IR or IR+ultrasound). Possibly some sort of movement detection on the security cameras.

    Or a magnetic loop sensor, which is my guess. (You’d see the other sensors.)